1. Field of the Invention
The invention relates to the field biochemical engineering, and particularly to a reclaimed water reuse device and a method for cleaning the same.
2. Description of the Related Art
The importance of the use of membranes in treatment of waste water is growing rapidly. With the advent of submerged membrane processes in which membrane modules are immersed in a large feed tank and filtrate is collected through suction applied to the filtrate side of the membrane, membrane bioreactors (MBRs) combining biological and physical processes into one stage promise to be more compact, efficient and economic. However, a non-neglectable problem with the MBR is that membrane modules are prone to contamination due to a lack of physical and chemical cleaning.
The most frequently used methods of physical cleaning include backwash and aeration. These methods need to be performed frequently and thus may influence the filtering process. During backwash, permeation through the membrane is stopped momentarily. Air or water flows through the membranes in a reverse direction to physically dislodge solids off of the membranes. During aeration, bubbles are produced in the tank water below the membranes. As the bubbles rise, they agitate or scrub the membranes and thereby dislodge some solids while creating an air lift effect and circulation of the tank water to carry the solids away from the membranes. The physical cleaning requires a large amount of aeration and energy, long cleaning time, and features comparatively poor cleaning quality.
Chemical cleaning is typically performed by removing membrane modules from the MBRs, and then immersing the membrane modules into a chemical solution. The chemical cleaning process may be complex and time-consuming.